Issue 67

A.Namdar et alii, Frattura ed Integrità Strutturale, 67 (2023) 118-136; DOI: 10.3221/IGF-ESIS.67.09

As part of a 2023-based study by Namdar et al., prediction of the cracked soil using XFEM was reported [5], and the type of crack was analyzed by considering crack propagation and mechanical properties of the material. The crack propagation angle is more prominent for a brittle material in comparison to a ductile material [1]. The crack will be propagated based on the mechanical properties of the material. The shape of the cracks and the possibility of crack propagation are associated with the mechanical properties of the materials [5]. In the present study, due to the nature of the seismic acceleration, mechanical properties of the soil, and geometry of different sections of the model constructed from the soil and recycled aggregate, the crack has not been propagated during the application of seismic load on the model. The lateral force from the slope of the embankment does not allow the crack propagation. Figs. 8 and 9 show the fluctuation of maximum dynamic nonlinear deformation produced by stress and strain in nodes 192 and 1434 of models 1-4. The maximum intensity of the stress and strain is observed when the model is located at a 24.9 km distance from the earthquake's epicenter. The deformation speed changes as the model's location from the earthquake's epicenter changes. An increase in displacement of the model leads to faster deformation. By comparing all models, it can be observed that the distribution of the deformation is nonlinear. Maximum deformation for all models was observed in the crest. Vertical strain and stress values vary for each model at nodes 192 and 1434. Tension cracks occur at the top of the embankment and not the bottom. When the embankment is subjected to seismic loading, the crest of the embankment fails due to tensile force, and the bottom part fails due to shear force [8]. Tensile failure precedes shear failure with low vertical stress. Due to this phenomenon, the crack will not be propagated in the embankment model when a preexisting crack during the embankment model is subjected to seismic acceleration. In this study, the crack has not been propagated from an initial condition of the model. The maximum intensity of the stress and strain is observed when the model is located at a 24.9 km distance from the earthquake's epicenter. The distance of the model plays an essential role in seismic stability. The stress-strain curve does not present shearing tensile in the model. When the compressive stress governs the model deformation, it does not cause crack propagation.

Model-1, Node 1434

Model-1, Node 192

0.0000 0.0005 0.0010 0.0015

0.0000 0.0005 0.0010 0.0015

0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005 Stress (MPa) Stress (MPa) Stress (MPa) Stress (MPa) 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005 0.0000 0.0005 0.0010 0.0015 Model-2, Node 1434 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005 0.0000 0.0005 0.0010 0.0015 Node-1434 Model-3, Node 1434 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005 0.0000 0.0005 0.0010 0.0015 Node-1434 Model-4, Node 1434 Time [s] 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-4, Node 1434 Strain Strain Strain Strain Time [s] Time [s] Time [s] Time [s] Time [s] Time [s] Time [s] 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-1, Node 1434 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-2, Node 1434 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-3, Node 1434

0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005 Stress (MPa)

Time [s]

Model-2, Node 192

0.0000 0.0005 0.0010 0.0015

0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005

0.0000 0.0005 0.0010 0.0015 Stress (MPa) Stress (MPa) Stress (MPa) -0.0015 -0.0010 -0.0005 0.0000 0.0005 0.0010 0.0015

Time [s]

Model-3, Node 192

0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.0015 -0.0010 -0.0005

Time [s]

Model-4, Node 192

Time [s] 0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Figure 8: Stress in models 1 – 4 at selected points.

0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-1, Node 192 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-2, Node 192 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-3, Node 192 0 1 2 3 4 5 6 7 8 9 1011121314151617181920 -0.00010 -0.00005 0.00000 0.00005 0.00010 Model-4, Node 192 Time [s] Time [s] Time [s] Strain Strain Strain Strain

Time [s]

Figure 9: Strain in models 1 - 4 at selected points.

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